Mature Cherry Tree Problem

We have a mature cherry tree, with about a 12" diameter trunk, which has dead branches and the leaves have almost all fallen off. The tree flowered in Spring but on some branches the buds never blossomed and turned brown. These are the branches that died.

Some leaves remain and some cherries are forming but the tree is nowhere near as prolific as last year. The grass around the tree is also turning brown. I have carefully removed the dead branches.

At first sight it seems like canker but there is no oozing gum. Could it be lacking water or nutrients? I'm wondering whether I should prune the tree severely to try and encourage it back to life!

I'd appreciate any clues as to what to do. The problem is that the cherries from this tree are delicious and formerly plentiful.                                                           
EDITIAN

where are you ??
Grass browning unless ground severely dried out seems indication of external influence such as weedkiller or aitborne pollution or excessive fertiliser application??
Pictures would help??
Has anyone else in your location similiar problems or other similiar trees such as almonds or aprocots etc affected
R

Our cherry is also looking very sick, not many leaves left on it at all.  Was saying to OH that I think it will have to come down, just thought it had got to the end of its life.  I'll have a good look at it tomorrow but seems funny there are so many sick cherries about just on this forum

When I find out how to attach pictures, I'll post some!

Here you go 

http://chat.allotment-garden.org/index.php?topic=19476.0

Thanks Yorkie,

Pics show the tree with its few small yellow-green leaves. The bird cherry next to it is healthy.

I also attach a picture of a cut branch. It's half alive and half dead. Never seen that before.

That is most bizarre 

I really don't know.  Do you have a local radio station with a gardening phone-in?  You can often email piccies to them and get advice from them.